BRITISH FOSSIL CORALS. 
lvi 
4. Genus MicRosoLENa. 
Lamouroux, Exp. méth., p. 65, 1821. 
Corallum differing from the preceding genus by the structure of the septa, the perfo- 
rations of which are much larger than in Coscimarea, and by the existence of a strong, 
common epitheca. 
Typ. sp., Microsolena porosa, Lamouroux, op. cit., tab. xxiv, fig. 24. 
5. Genus GONIOPORA. 
Quoy and Gaimard, Voy. de l’Astr., Zooph., p. 218, 1833 ; Goniopora and Porastrea, Milne Edw. and 
J. Haime, Comptes rend. de l’Acad. des Se., t. xxvii, p. 496, 1848. 
Corallum having distinct, elevated walls, of a fenestrate structure. Calices deep. 
Columella spongy. Septa well developed, and fenestrate. No pali. 
Typ. sp., Gontopora pedunculata, Quoy and Gaimard, Voyage de |’Astrolabe, Zooph., tab. xvi, 
figs. 9-11. 
6. Genus RHODARMA. 
Milne Edw. and J. Haime, Comptes rend., t. xxix, p. 259, 1849. 
Corallum with thick walls, rather high. Sepéa rudimentary. Pali greatly developed, 
and forming a rosette in the centre of the calice. 
Typ. sp., Rhodarea calicularis, nob.; Astrea calicularis, Lamarck, Hist. des An. sans Vert., t. ii, 
p. 266. 
7. Genus PoRARMA. 
Milne Edw. and J. Haime, Comptes rend., t. xxix, p. 259, 1849. 
Walls thin, and widely fenestrated. Seyta formed by a series of spiniform processes, 
which sometimes ramify towards the centre of the visceral cavity, so as to constitute a sort 
of spurious columella. 
Typ. sp., Porarea fenestrata, nob. ; Pocillopora fenestrata, Lamarck, Hist. des An. sans Vert., t. ii, 
p-. 275 ; Milne Edw. and J. Haime, Ann. des Se. Nat., 3™° série, vol. ix, fig. 1. 
8. Genus HoLaRma. 
Milne Edw. and J. Haime, Comptes rend., t. xxix, p. 259, 1849. 
Calices with distinct polygonal margins, rather deep. Septal apparatus composed of 
irregular trabicule, completely blended with the walls, and constituting thus a delicate 
spongy mass. Co/wmella fasciculate and short. 
Typ. sp., Holarea Parisiensis, nob. ; Alveolites Parisiensis, Michelin, Icon. Zooph., pl. xlv, fig, 10. 
